def unblock(self):
'''
'''
st,output = getstatusoutput("pfctl -a switchyard -Fr") # flush rules
log_debug("Flushing rules: {}".format(output))
st,output = getstatusoutput("pfctl -X {}".format(self._token))
log_info("Releasing pf: {}".format(output.replace('\n', '; ')))
def __init__(self, interfaces, rules):
super().__init__(interfaces, rules)
self._intf = interfaces
st,output = getstatusoutput("iptables-save")
self._saved_iptables = output
self._arpignore = {}
self._rulecmds = [ 'iptables -F', 'iptables -t raw -F' ]
# --protocol {} -i {} --port {}
doall = False
for r in rules:
cmds = self._parse_rule(r)
self._rulecmds.extend(cmds)
if r == 'all':
doall = True
if doall:
badintf = []
for intf in interfaces:
st,output = getstatusoutput('sysctl net.ipv4.conf.{}.arp_ignore'.format(intf))
if st != 0:
badintf.append(intf)
continue
self._arpignore[intf] = int(output.split()[-1])
st,output = getstatusoutput('sysctl -w net.ipv4.conf.{}.arp_ignore=8'.format(intf))
for intf in badintf:
self._intf.remove(intf) # alias of interfaces, so just remove
# from self._intf
log_debug("Rules to install: {}".format(self._rulecmds))
def send_packet(self, dev, packet):
'''
Send a Switchyard Packet object on the given device
(string name of device).
Raises SwitchyException if packet object isn't valid, or device
name isn't recognized.
'''
if isinstance(dev, int):
dev = self._lookup_devname(dev)
if isinstance(dev, Interface):
dev = dev.name
pdev = self.pcaps.get(dev, None)
if not pdev:
raise SwitchyException(
"Unrecognized device name for packet send: {}".format(dev))
else:
if packet is None:
raise SwitchyException("No packet object given to send_packet")
if not isinstance(packet, Packet):
raise SwitchyException(
"Object given to send_packet is not a Packet (it is: {})".
format(type(packet)))
# convert packet to bytes and send it
rawpkt = packet.to_bytes()
log_debug("Sending packet on device {}: {}".format(
dev, str(packet)))
pdev.send_packet(rawpkt)
def block(self):
'''
pfctl -a switchyard -f- < rules.txt
pfctl -a switchyard -F rules
pfctl -t switchyard -F r
'''
st,output = _sendcmd(["/sbin/pfctl","-aswitchyard", "-f-"], self._rules)
log_debug("Installing rules: {}".format(output))
def _recv(self, nbytes):
try:
data, sourceaddr, destaddr = self._socket_queue_from_stack.get(
block=self._block, timeout=self._timeout)
log_debug("recv from {}<-{}:{}".format(data, sourceaddr, destaddr))
return data, sourceaddr, destaddr
except Empty as e:
pass
log_debug("recv timed out")
raise timeout("timed out")
def bind(self, address):
# block firewall port
# set stack to only allow packets through for addr/port
self._local_addr = address
# update firewall and pcap filters
log_debug(
"Updating firewall/bpf rule on bind(): {} dst port {}".format(
self._protoname, self._local_addr[1]))
Firewall.add_rule("{}:{}".format(self._protoname, self._local_addr[1]))
PcapLiveDevice.set_bpf_filter_on_all_devices("{} dst port {}".format(
self._protoname, self._local_addr[1]))
def _sig_handler(self, signum, stack):
'''
Handle process INT signal.
'''
log_debug("Got SIGINT.")
if signum == signal.SIGINT:
PyLLNet.running = False
if self.pktqueue.qsize() == 0:
# put dummy pkt in queue to unblock a
# possibly stuck user thread
self.pktqueue.put( (None,None,None) )
self.pktqueue = Queue()
def _sig_handler(self, signum, stack):
'''
Handle process INT signal.
'''
log_debug("Got SIGINT.")
if signum == signal.SIGINT:
PyLLNet.running = False
if self.pktqueue.qsize() == 0:
# put dummy pkt in queue to unblock a
# possibly stuck user thread
self.pktqueue.put((None, None, None))
self.pktqueue = Queue()
def __init__(self, interfaces, rules):
super().__init__(interfaces, rules)
self._interfaces = interfaces
for r in rules:
cmds = self._parse_rule(r)
self._rules.extend(cmds)
st,output = getstatusoutput("pfctl -E")
mobj = re.search("Token\s*:\s*(\d+)", output, re.M)
if mobj is None:
raise RuntimeError("Couldn't get pfctl token. Are you running as root?")
self._token = mobj.groups()[0]
log_debug("Rules to install: {}".format(self._rules))
log_info("Enabling pf: {}".format(output.replace('\n', '; ')))
def __low_level_dispatch(pcapdev, devname, pktqueue):
'''
Thread entrypoint for doing low-level receive and dispatch
for a single pcap device.
'''
count = 0
while PyLLNet.running:
# a non-zero timeout value is ok here; this is an
# independent thread that handles input for this
# one pcap device. it throws any packets received
# into the shared queue (which is read by the actual
# user code)
pktinfo = pcapdev.recv_packet(timeout=0.2)
if pktinfo is None:
continue
log_debug("Got packet on device {}, dlt {}".format(devname, pcapdev.dlt))
pktqueue.put( (devname,pcapdev.dlt,pktinfo) )
count += 1
if count % 100 == 0:
stats = pcapdev.stats()
log_debug("Periodic device statistics {}: {} received, {} dropped, {} dropped/if".format(devname, stats.ps_recv, stats.ps_drop, stats.ps_ifdrop))
log_debug("Receiver thread for {} exiting".format(devname))
stats = pcapdev.stats()
log_debug("Final device statistics {}: {} received, {} dropped, {} dropped/if".format(devname, stats.ps_recv, stats.ps_drop, stats.ps_ifdrop))
def __low_level_dispatch(pcapdev, devname, pktqueue):
'''
Thread entrypoint for doing low-level receive and dispatch
for a single pcap device.
'''
count = 0
while PyLLNet.running:
# a non-zero timeout value is ok here; this is an
# independent thread that handles input for this
# one pcap device. it throws any packets received
# into the shared queue (which is read by the actual
# user code)
pktinfo = pcapdev.recv_packet(timeout=0.2)
if pktinfo is None:
continue
log_debug("Got packet on device {}, dlt {}".format(
devname, pcapdev.dlt))
pktqueue.put((devname, pcapdev.dlt, pktinfo))
count += 1
if count % 100 == 0:
stats = pcapdev.stats()
log_debug(
"Periodic device statistics {}: {} received, {} dropped, {} dropped/if"
.format(devname, stats.ps_recv, stats.ps_drop,
stats.ps_ifdrop))
log_debug("Receiver thread for {} exiting".format(devname))
stats = pcapdev.stats()
log_debug(
"Final device statistics {}: {} received, {} dropped, {} dropped/if"
.format(devname, stats.ps_recv, stats.ps_drop, stats.ps_ifdrop))
def __init__(self, family, xtype, proto=0, fileno=0):
family = AddressFamily(family)
if family != AddressFamily.AF_INET:
raise NotImplementedError(
"socket for family {} not implemented".format(family))
if xtype not in [SOCK_DGRAM, SOCK_STREAM]:
raise NotImplementedError(
"socket type {} not implemented".format(xtype))
self._family = family
self._socktype = xtype
self._protoname = 'udp'
self._proto = IPProtocol.UDP
if self._socktype == SOCK_STREAM:
self._protoname = 'tcp'
self._proto = IPProtocol.TCP
self._timeout = None
self._block = True
self._remote_addr = (None, None)
self._local_addr = ('0.0.0.0', _get_ephemeral_port())
log_debug("Adding firewall/bpf rule {} dst port {}".format(
self._protoname, self._local_addr[1]))
try:
Firewall.add_rule("{}:{}".format(self._protoname,
self._local_addr[1]))
# only get packets with destination port of local port, or any
# icmp packets
PcapLiveDevice.set_bpf_filter_on_all_devices(
"{} dst port {} or icmp".format(self._protoname,
self._local_addr[1]))
except:
with yellow():
print(
"Unable to complete socket emulation setup (failed on firewall/bpf filter installation). Did you start the program via srpy?"
)
import traceback
print("Here is the raw exception information:")
with red():
print(indent(traceback.format_exc(), ' '))
sys.exit()
ApplicationLayer.init()
self._socket_queue_to_stack, self._socket_queue_from_stack = ApplicationLayer.queues(
)
def send_packet(self, dev, packet):
'''
Send a Switchyard Packet object on the given device
(string name of device).
Raises SwitchyException if packet object isn't valid, or device
name isn't recognized.
'''
pdev = self.pcaps.get(dev, None)
if not pdev:
raise SwitchyException("Unrecognized device name for packet send: {}".format(dev))
else:
if packet is None:
raise SwitchyException("No packet object given to send_packet")
if not isinstance(packet, Packet):
raise SwitchyException("Object given to send_packet is not a Packet (it is: {})".format(type(packet)))
# convert packet to bytes and send it
rawpkt = packet.to_bytes()
log_debug("Sending packet on device {}: {}".format(dev, str(packet)))
pdev.send_packet(rawpkt)
def __init__(self, devlist, name=None):
LLNetBase.__init__(self)
signal.signal(signal.SIGINT, self._sig_handler)
signal.signal(signal.SIGTERM, self._sig_handler)
signal.signal(signal.SIGHUP, self._sig_handler)
signal.signal(signal.SIGUSR1, self._sig_handler)
signal.signal(signal.SIGUSR2, self._sig_handler)
self.devs = devlist # self.__initialize_devices(includelist, excludelist)
self.devinfo = self.__assemble_devinfo()
self.pcaps = {}
self.__make_pcaps()
log_info("Using network devices: {}".format(' '.join(self.devs)))
for devname, intf in self.devinfo.items():
log_debug("{}: {}".format(devname, str(intf)))
PyLLNet.running = True
self.__spawn_threads()
if name:
self.__name = name
else:
self.__name = gethostname()
def __init__(self, devlist, name=None):
LLNetBase.__init__(self)
signal.signal(signal.SIGINT, self._sig_handler)
signal.signal(signal.SIGTERM, self._sig_handler)
signal.signal(signal.SIGHUP, self._sig_handler)
signal.signal(signal.SIGUSR1, self._sig_handler)
signal.signal(signal.SIGUSR2, self._sig_handler)
self.devs = devlist # self.__initialize_devices(includelist, excludelist)
self.devinfo = self.__assemble_devinfo()
self.pcaps = {}
self.__make_pcaps()
log_info("Using network devices: {}".format(' '.join(self.devs)))
for devname, intf in self.devinfo.items():
log_debug("{}: {}".format(devname, str(intf)))
PyLLNet.running = True
self.__spawn_threads()
if name:
self.__name = name
else:
self.__name = gethostname()
def shutdown(self):
'''
Should be called by Switchyard user code when a network object is
being shut down. (This method cleans up internal threads and network
interaction objects.)
'''
if not PyLLNet.running:
return
PyLLNet.running = False
log_debug("Joining threads for shutdown")
for t in self.threads:
t.join()
log_debug("Closing pcap devices")
for devname,pdev in self.pcaps.items():
pdev.close()
log_debug("Done cleaning up")
def shutdown(self):
'''
Should be called by Switchyard user code when a network object is
being shut down. (This method cleans up internal threads and network
interaction objects.)
'''
if not PyLLNet.running:
return
PyLLNet.running = False
log_debug("Joining threads for shutdown")
for t in self.threads:
t.join()
log_debug("Closing pcap devices")
for devname, pdev in self.pcaps.items():
pdev.close()
log_debug("Done cleaning up")
def shutdown(self):
self.__linkem.shutdown()
self.__done = True
log_debug("Joining node codeexec thread {} node {}".format(self.__t.name, self.__name))
self.__t.join()
def setup_switchyard_stack(proto, localaddr):
log_debug("Starting up stack thread")
ApplicationLayer.init()
return ApplicationLayer.queues()
def _send(self, data, remote_addr):
log_debug("socketemu send: {}->{}:{}".format(data, self._local_addr,
remote_addr))
self._socket_queue_to_stack.put((data, self._local_addr, remote_addr))
def add_rule(self, rule):
for cmd in self._parse_rule(rule):
st,output = getstatusoutput(cmd)
self._rulecmds.append(cmd)
log_debug("Adding firewall rule: {}".format(cmd))
def add_rule(self, rule):
cmds = self._parse_rule(rule)
self._rules.extend(cmds)
st,output = _sendcmd(["/sbin/pfctl","-aswitchyard", "-f-"], cmds)
log_debug("Adding firewall rules: {}".format(cmds))
def shutdown(self):
self.__linkem.shutdown()
self.__done = True
log_debug("Joining node codeexec thread {} node {}".format(
self.__t.name, self.__name))
self.__t.join()
def add_rule(self, rule):
for cmd in self._parse_rule(rule):
st, output = getstatusoutput(cmd)
self._rulecmds.append(cmd)
log_debug("Adding firewall rule: {}".format(cmd))
def __del__(self):
log_debug("Exiting socket code")
